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From: Linus Torvalds <torvalds@linux-foundation.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.cz>, Greg KH <greg@kroah.com>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	LKML <linux-kernel@vger.kernel.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Maciej Rutecki <maciej.rutecki@gmail.com>
Subject: Re: [PATCH] sysfs: Optionally count subdirectories to support buggy applications
Date: Wed, 1 Feb 2012 15:15:14 -0800	[thread overview]
Message-ID: <CA+55aFyNQnXrL7fWhBt4LYBuoHD_x+j=Af-N=ueFMBkymy9Rnw@mail.gmail.com> (raw)
In-Reply-To: <m1ehueyz20.fsf_-_@fess.ebiederm.org>

On Wed, Feb 1, 2012 at 2:21 PM, Eric W. Biederman <ebiederm@xmission.com> wrote:
>
> lm_sensors and possibly other applications get confused if all sysfs
> directories return nlink == 1.  The lm_sensors code that got confused
> was just wrong and a fixed version of lm_sensors should be released
> shortly.

I think this patch is horrible, and broken.

And making the feature a config option is just stupid.

The simple approach is to

 - implement a inode->i_op->getattr function for sysfs

 - make it call generic_fillattr()

 - after filling in the generic fields, count the number of sysfs
children it has and update stat->nlink appropriately.

No extra "keep track of inode counts by hand" crap, and no idiotic
config options that just make it easy to (conditionally) get things
wrong. Just do it right, and do it *unconditionally* right.

The Linux VFS layer is smart, and allows filesystems to do these kinds
of fixups.

                  Linus

  parent reply	other threads:[~2012-02-01 23:15 UTC|newest]

Thread overview: 75+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-30 21:56 sysfs regression: wrong link counts Jiri Slaby
2012-01-30 22:06 ` Greg KH
2012-01-30 22:10   ` Alan Cox
2012-01-30 22:27     ` Greg KH
2012-01-30 22:43       ` Al Viro
2012-01-30 22:56         ` Al Viro
2012-01-31  1:27       ` Eric W. Biederman
2012-01-31 10:48         ` Jiri Slaby
2012-01-31 12:44           ` Eric W. Biederman
2012-01-31 16:45             ` Linus Torvalds
2012-01-31 19:18               ` Al Viro
2012-02-01  5:06               ` Eric W. Biederman
2012-02-01 22:21                 ` [PATCH] sysfs: Optionally count subdirectories to support buggy applications Eric W. Biederman
2012-02-01 22:24                   ` Greg Kroah-Hartman
2012-02-01 22:44                     ` Eric W. Biederman
2012-02-01 22:49                       ` Greg Kroah-Hartman
2012-02-01 22:31                   ` Dave Jones
2012-02-01 22:35                   ` Jiri Slaby
2012-02-01 23:15                   ` Linus Torvalds [this message]
2012-02-01 23:18                     ` Linus Torvalds
2012-02-02  1:22                       ` Al Viro
2012-02-02 21:24                         ` [RFC] killing boilerplate checks in ->link/->mkdir/->rename Al Viro
2012-02-02 23:46                           ` Linus Torvalds
2012-02-03  1:16                             ` Al Viro
2012-02-03  1:45                               ` Al Viro
2012-02-03  2:00                                 ` Linus Torvalds
2012-02-03 14:57                               ` Chris Mason
2012-02-03 17:08                               ` Al Viro
2012-02-03 19:34                                 ` Artem Bityutskiy
2012-02-06  8:50                                 ` Artem Bityutskiy
2012-02-06 13:56                                   ` Al Viro
2012-02-06 17:05                                     ` Artem Bityutskiy
2012-02-06 17:11                                       ` Al Viro
2012-02-07  7:21                                         ` Artem Bityutskiy
2012-02-06 22:49                               ` Dave Chinner
2012-02-03  8:25                           ` Andreas Dilger
2012-02-03 17:03                             ` Al Viro
2012-02-04  7:42                               ` Andreas Dilger
2012-03-05 13:30                       ` [PATCH] sysfs: Optionally count subdirectories to support buggy applications Jiri Slaby
2012-03-05 16:09                         ` Greg Kroah-Hartman
2012-03-05 16:47                           ` Linus Torvalds
2012-03-08 21:05                             ` Greg Kroah-Hartman
2012-03-08 22:18                             ` Eric W. Biederman
2012-03-08 23:40                               ` Linus Torvalds
2012-03-08 21:28                           ` Eric W. Biederman
2012-03-08 21:34                           ` [PATCH 1/3] sysfs: Compact sysfs_dirent s_flags into a byte Eric W. Biederman
2012-03-08 21:36                             ` [PATCH 2/3] sysfs: Maintain usable nlink directory counts Eric W. Biederman
2012-03-08 21:37                               ` [PATCH 3/3] sysfs: Remove SYSFS_FLAG_REMOVED and use sd->s_nlink == 0 instead Eric W. Biederman
2012-03-09  3:40                                 ` Linus Torvalds
2012-03-08 22:28                             ` [PATCH 1/3] sysfs: Compact sysfs_dirent s_flags into a byte Greg Kroah-Hartman
2012-03-09  2:49                               ` Eric W. Biederman
2012-01-31  3:45     ` sysfs regression: wrong link counts Eric W. Biederman
2012-01-31 11:54       ` Alan Cox
2012-01-30 22:52 ` Kay Sievers
2012-01-31 10:41   ` network regression: cannot rename netdev twice Jiri Slaby
2012-01-31 10:52     ` Kay Sievers
2012-01-31 11:00       ` Jiri Slaby
2012-01-31 11:13         ` Kay Sievers
2012-01-31 11:17           ` Jiri Slaby
2012-01-31 11:58             ` Kay Sievers
2012-01-31 14:18               ` Eric W. Biederman
2012-01-31 14:40                 ` [PATCH] sysfs: Update the name hash when renaming sysfs entries Eric W. Biederman
2012-01-31 14:41                   ` Jiri Slaby
2012-01-31 14:55                   ` Greg KH
2012-02-04  2:14       ` network regression: cannot rename netdev twice Henrique de Moraes Holschuh
2012-02-06 20:03         ` Kay Sievers
2012-02-08  2:00           ` Henrique de Moraes Holschuh
2012-02-08  3:50             ` Kay Sievers
2012-02-08  6:42               ` Valdis.Kletnieks
2012-02-08 10:57                 ` Kay Sievers
2012-02-08 20:06                   ` Valdis.Kletnieks
2012-02-08 20:27                     ` Stephen Hemminger
2012-02-08 23:48                     ` Kay Sievers
2012-01-31  1:32 ` sysfs regression: wrong link counts Eric W. Biederman
2012-02-01 18:29 ` Maciej Rutecki

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